HULL, Mass. - In the final months of Rebecca Riley's life, a school nurse said the little girl was so weak she was like a "floppy doll."

The preschool principal had to help Rebecca off the bus because the 4-year-old was shaking so badly.

And a pharmacist complained that Rebecca's mother kept coming up with excuses for why her daughter needed more and more medication.

None of their concerns was enough to save Rebecca.

Rebecca - who had been diagnosed with attention deficit hyperactivity and bipolar disorder, or what used to be called manic depression - died Dec. 13 of an overdose of prescribed drugs, and her parents have been arrested on murder charges, accused of intentionally overmedicating their daughter to keep her quiet and out of their hair.

Interviews and a review of court documents by The Associated Press make it clear that many of those who were supposed to protect Rebecca - teachers, social workers, other professionals - suspected something was wrong, but never went quite far enough.

But the tragic case is more than a story about one child. It raises troubling, larger questions about the state of child psychiatry, namely: Can children as young as Rebecca be accurately diagnosed with mental illnesses? Are rambunctious youngsters being medicated for their parents' convenience? And should children so young be prescribed powerful psychotropic drugs meant for adults?

Dispensing drugs to children diagnosed with mood or behavior problems is "the easiest thing to do, but it's not always the best thing to do," said Dr. Jon McClellan, medical director of the Child Study and Treatment Center in Lakewood, Wash. "At some level, I would hope that you'd also be teaching kids ways to control their behavior."

According to the medical examiner, Rebecca died of a combination of Clonidine, a blood pressure medication Rebecca had been prescribed for ADHD; Depakote, an antiseizure and mood-stabilizing drug prescribed for the little girl's bipolar disorder; a cough suppressant; and an antihistamine. The amount of Clonidine alone in Rebecca's system was enough to be fatal, the medical examiner said.

The two brand-name prescription drugs are approved by the Food and Drug Administration for use in adults only, though doctors can legally prescribe them to youngsters and do so frequently.

Rebecca's parents, Michael and Carolyn Riley, say they were only following doctor's orders. Rebecca, they told police, had been diagnosed when she was just 2Â½, and Rebecca's psychiatrist prescribed the same potent drugs that had been prescribed for her older brother and sister when she diagnosed them with the same illnesses several years earlier.

But Rebecca's teachers, the school nurse and her therapist all told police they never saw behavior in Rebecca that fit her diagnoses, such as aggression, sharp mood swings or hyperactivity.

Prosecutors say the Rileys intentionally tried to quiet their daughter with high doses of Clonidine. Relatives told police the Rileys called Clonidine the "happy medicine" and the "sleep medicine."

Kifuji did not return calls for comment and declined to be interviewed. But Kifuji has vehemently denied any role in Rebecca's death. She has agreed to a suspension of her license while the state's medical board investigates.

Kifuji told police Rebecca had been her patient since August 2004, when she was 2. She said she based her diagnoses of ADHD and bipolar disorder on the family's mental health history, as described by Carolyn Riley, and Rebecca's behavior, as described by Carolyn and briefly observed by her during office visits.

Kifuji told police she became alarmed in October 2005 when Carolyn Riley told her she had increased Rebecca's nighttime dose of Clonidine from 2 to 2Â½ tablets, and warned Carolyn the increased dose could kill Rebecca.

But Carolyn told investigators Kifuji told her she could give Rebecca and her sister extra Clonidine at night to help them sleep.

In the months leading up to Rebecca's death, others noticed there was something wrong.

Teachers and staff members at the Johnson Early Childhood Center in Weymouth, about 20 miles south of Boston, say they called Rebecca's mother repeatedly to tell her that Rebecca was "out of it," but her mother said the girl was tired because she wasn't sleeping well.

A neighbor who lived next door to the family in the last month of Rebecca's life said Rebecca and her siblings seemed listless.

Pharmacists at Walgreens in Weymouth called Kifuji twice to complain that Carolyn Riley was asking for more Clonidine, even though her prescription was not due to be refilled yet, according to state police.

Once, Riley said she had lost a bottle of pills, and another time, she said water had gotten into her prescription bottle and ruined the pills, according to police.

Kifuji authorized refills, but after the second incident, she began prescribing Clonidine in 10-day refills instead of 30-day supplies, investigators said.

On Aug. 16, a prescription for 35 Clonidine tablets - a 10-day supply - was filled at Walgreens, even though the Rileys had obtained a 10-day refill only the day before, investigators said.

Walgreens spokeswoman Tiffani Bruce said: "The scrip was filled as written, as it was prescribed by the doctor, and all the appropriate information on the medications was given to the family."

After Rebecca's death, police found only seven Clonidine tablets in the family's medicine tray; the pharmacist said there should have been 75. All together, prosecutors say, Carolyn Riley got 200 more pills in one year than she should have.

The Rileys' lawyers call them unsophisticated people who did not question their children's doctors. Both were unemployed; they collected welfare and disabilty benefits and lived in subsidized housing. Michael Riley, who is also awaiting trial on charges of molesting a stepdaughter in 2005, claimed to suffer from bipolar disorder and a rage disorder; his wife told police she suffered from depression and anxiety. "They are not the sort of people who go on the Internet and look on WebMD. These are the sort of people who, when they go to a doctor, the doctor is God and they do what the doctor says," said John Darrell, Michael's lawyer. Carolyn's lawyer, Michael Bourbeau, said that because the Rileys' three children were all taking Clonidine, Rebecca's prescription may have come up short at times when her siblings were given some of her pills. And some of the pills may have been lost when they were split in half, he said. In July, after a therapist filed a complaint with the state Department of Social Services, social workers met with the family's doctors and other medical professionals and were assured that the medications Rebecca was taking were within medical guidelines. "There were lots of medical eyes on this case and none of them seemed to say there was an issue of over-medication in this case," said Social Services Commissioner Harry Spence, who has come under fire for the agency's handling of the case. Still, there were lingering concerns. When social workers tried to make a home visit in November, Carolyn "resisted and evaded," Spence said. Weeks later, workers resolved to make a surprise check, but Rebecca died the very next day, before they could visit. Rebecca was found dead on the floor of her parents' bedroom wearing only a pink pull-up diaper and gold-stud earrings, on top of a pile of clothes, magazines and a stuffed brown bear. Rebecca's uncle, James McGonnell, and his girlfriend, Kelly Williams, who lived with the Rileys, told police that the Rileys would put their kids to bed as early as 5 p.m. Rebecca, they said, often slept through the day and got up only to eat. When Michael Riley decided the kids were "acting up," he told Carolyn to give them pills, McGonnell and Williams told police. According to McGonnell and Williams, Rebecca spent the last days of her life wandering around the house, sick and disoriented. But the Rileys told police they were not alarmed. "It was just a cold," Carolyn repeatedly said during police interviews. The medical examiner said Rebecca died a slow and painful death. She said the overdose of Clonidine caused her organs to shut down, filling her lungs with fluid and causing congestive heart failure. Williams told police that the night before she died, Rebecca was pale and seemed "out of it." At one point, the little girl knocked weakly on her parents' bedroom door and softly called for her mommy, but Michael Riley opened the door a crack and yelled at her to go back to her room, Williams said. Later that night, McGonnell told police, he heard someone struggling to breathe and found Rebecca gurgling as if something was stuck in her throat. McGonnell told police he wiped vomit from his niece's face, then kicked in the door to her parents' room and yelled at the Rileys to take Rebecca to the emergency room. Instead, Carolyn Riley said, she gave her daughter a half-tablet of Clonidine. Carolyn's mother, Valerie Berio, said that when she visited the kids the night of Dec. 11, Rebecca seemed congested but not seriously ill. In a photograph Berio said she took that night, Rebecca is smiling slightly as her mother holds a new green velvet dress in front of her. Berio said that shows that her daughter and son-in-law could not have known how sick Rebecca was. Rebecca's death has inflamed a long-running debate in psychiatry. Some psychiatrists believe bipolar disorder, which was traditionally diagnosed in adolescence or early adulthood, has become a trendy diagnosis in young children. "As a clinician, I can tell you it's just very difficult to say whether someone is just throwing tantrums or has bipolar disorder," said Dr. Oscar B. Bukstein, a child psychiatrist and associate professor at the University of Pittsburgh. A study of mentally ill children discharged from community hospitals, published in January in the Archives of General Psychiatry, found the proportion of children diagnosed with bipolar disorders jumped from 2.9 percent in 1990 to 15.1 percent in 2000. A report released by the Centers for Disease Control and Prevention in 2002 estimated that about 7 percent of elementary school-age children - or approximately 1.6 million youngsters ages 6 to 11 - have been diagnosed with ADHD. The annual number of U.S. children prescribed anti-psychotic drugs jumped fivefold between 1995 and 2002, to an estimated 2.5 million, according to a study published last year by researchers at Vanderbilt Children's Hospital in Nashville, Tenn. Some child psychiatrists say bipolar disorder may have been under-diagnosed in children for years, partly because several key symptoms are also symptoms of ADHD, including hyperactivity, distractibility and talkativeness. Dr. Janet Wozniak, director of the Pediatric Bipolar Disorder Research Program at Massachusetts General Hospital, said early diagnosis and treatment are critical because the illness can cause social and academic problems, and lead to drug abuse, crime and suicide. "What's commonly overlooked when considering diagnosing and treating children at such an early age is the risk of not treating and not intervening," Wozniak said. AP-CS-03-23-07 1459EDT